Second base has been one of the major holes for the Athletics this season. The five players the A's have used there - Eric Sogard, Adam Rosales, Jed Lowrie, Andy Parrino, and Scott Sizemore - have combined for a .682 OPS while manning the position, which is the second-worst positional split on the club. Oakland second basemen have hit a collective .264/.339/.343, and of the five men mentioned, only Sogard has hit a home run while playing the keystone.

Enter Grant Green. The team's first-round draft selection from 2009 has a .828 OPS since being promoted to Triple-A Sacramento before the start of the 2012 season, and his 11 home runs through 81 games has been his best pace since his 20-home run campaign of 2010. He will not be able to continue that pace, as the A's called him up Monday. He should at least take over the right-handed half of the platoon with Sogard, but there is a very good chance he takes on more playing time than that. The fact that the A's have yet to touch Jemile Weeks this season does not bode well for his future with the organization.

Ryan Howard hit the disabled list over the weekend because of a recurrence of soreness in his left knee, and he is bound for an MRI. Instead of just shuffling around the usual suspects at the position (John Mayberry, Kevin Frandsen, Laynce Nix), the Phillies decided to recall Darin Ruf from Triple-A Lehigh Valley. Ruf was hardly a blip on most people's fantasy radars until his age-25 season, when he hit 38 home runs for Double-A Reading. Now 25-year-olds playing Double-A for the first time do not typically amount to much, but those who hit 38 home runs area bit more interesting.

He has come back down to earth a bit this season, with seven home runs in 81 games, but he has been learning how to play left field, which is something of an uncomfortable position for him. He can rest easy knowing he will primarily play first base during this stay in the majors. However, whether his Double-A power will translate to the majors remains to be seen. We should be given a chance to find out, though, depending on the length of Howard's injury.

At one point this season, Didi Gregorius made 33 consecutive starts at shortstop for the Diamondbacks. He has hit .197 over the past month (79 plate appearances) since his batting average hit an apex of .322. The slide could not have come at a worse time, as Aaron Hill's return to action at second has availed Cliff Pennington to play shortstop more frequently. Gregorius had three apparent healthy scratches over the week that was, and the non-starts have been more attributable to Gregorius' struggles than Pennington playing well. Pennington's batting average has not been above .250 since the second week of April, so he will likely find himself back on the bench once Gregorius works out some of the kinks in his bat.

Tyler Flowers was supposed to be the White Sox's catcher of the future when they traded for him prior to the 2009 season. Now, he's just fighting to be their catcher of the present. The White Sox recalled Josh Phegley from Triple-A Charlotte on Friday after Flowers started his first season as the White Sox's primary catcher with a .208/.260/.372 line. He had eight home runs over his first 200-ish at-bats, but he also had nearly seven times as many strikeouts (70) as walks (11). Phegley came up Friday, and he started two of the White Sox's three games against the Rays. He has below-average defense, but he was in the midst of an offensive breakout (.316/.368/.597 in 231 at-bats) at Triple-A Charlotte prior to his recall. This was completely out of line with his previous two seasons (.666 OPS in 2011, .680 in 2012), but he is now further removed from a rare blood disorder. By all accounts, the playing time edge should go to the catcher with the hottest bat, and Flowers and Phegley could also see time at DH if the White Sox recall a third catcher or feel confident in their emergency options.

Jose Tabata returned from the disabled list just before July 4, which coincided with Travis Snider coping with a minor foot injury. Tabata has not missed a start in right since returning, while Snider has only logged five late-game at-bats since Tabata's return. Snider has delivered some capable defense in right and some big hits at the plate this season, but his OBP has dipped back below .300, and the once-powerful minor league slugger only has 16 extra-base hits (three home runs) in 219 at-bats. Tabata has been a roll since returning (7-for-17, three doubles, one steal), and he could continue to snatch starts in right as long as the hits continue to fall. Pirates right fielders have only hit .235/.301/.380 on the season, and this is a spot the Pirates could address via the trade market as they battle the Cardinals and Reds for the NL Central crown.

Ike Davis' struggles have made Mets first base one of the most-frequently covered positions in this year's In Some Depth series. Hopefully this mention will be one of the last. Davis returned to the Mets on Friday after nearly a month at Triple-A Las Vegas. He hit .293/.424/.667 in his 92 plate appearances at the Triple-A level, but his renewed confidence is more important than the actual stats down there. The Mets appear to still be a bit hesitant about starting Davis against lefties, as evidenced by Josh Satin's start against the left-handed Tom Gorzelanny on Sunday. One would think this is not a straight platoon, and it may weaken as Satin's bat cools. Lucas Duda, who had initially taken over first base from Davis, is progressing slowly from an oblique injury, and he may be headed back to the outfield once healthy.

Like the aforementioned Ike Davis, Dustin Ackley was banished to the minor leagues for a month to try to re-gain some confidence in his offense. UnlIke Davis, Ackley returned to the majors with a new defensive position. He has started in center field for seven of the Mariners' nine games since returning from Triple-A. He appears to be adjusting to his new position, but his production at the plate remains largely the same. He is just 5-for-27 (.185) since returning, with six strikeouts to two walks. His string of starts should be occasionally interrupted when Endy Chavez or Michael Saunders move over from one of the corner outfield spots. Still, there should be no immediate threat to Ackley's everyday action until Franklin Gutierrez returns from a hamstring injury.

Clete Thomas had the two best weeks of his season for the second week of June while he filled in in center field for the injured Aaron Hicks. From June 11 through July 1, he slashed .294/.368/.485 with three home runs and four doubles (he also had 21 strikeouts and three caught-stealings over the 18-game stretch). However, his run of everyday playing time came a halt once the calendar turned and Hicks returned from the disabled list. Hicks has hit considerably better since returning from the disabled list than before, going 6-for-21 with a home run and two steals over six games. He should continue to start unencumbered in center, while Thomas will have to scrape for innings all over the outfield.

For the majority of the season, the Cubs have utilized a platoon in right field, with Nate Schierholtz facing right-handed pitchers and Scott Hairston in the field against lefties. That situation changed Sunday night/Monday morning when the Cubs dealt Hairston to the Nationals. The trade may have a positive impact on Schierholtz's playing time if the Cubs decide to throw him out there against lefties instead of someone like Dave Sappelt. However, starts against lefties could have a negative impact on his averages. The Cubs have been cognizant of his short-comings against same-handed pitchers, and hence he has zero starts (and only 25 at-bats total) against left-handed pitchers this season. Schierholtz himself is likely on the trade block. Minor league outfielders to keep an eye on include Brett Jackson, who continues to struggle to make contact (and is currently on the 7-day DL at Iowa), and Matt Szczur, who has 20 steals in 29 attempts for Double-A Tennessee.

Jose Iglesias would be atop the depth chart here, but he is currently covering short for the DL'd Stephen Drew. Actually, Will Middlebrooks would probably be on top, but he is currently at Triple-A Pawtucket, regaining confidence in his swing. Hence, Brandon Snyder and Brock Holt are the Red Sox's men at the hot corner for the immediate future. Snyder started five straight games last week before giving way to Holt for matchup-related reasons. Holt entered the weekend with all of seven games of third base experience in the minors, so he will likely give way to Snyder on most nights. Meanwhile, Middlebrooks is tearing up the International League (.619 slugging percentage over his last 10 games), and he had a four-hit, eight-RBI game against Scranton/Wilkes-Barre last week. The Red Sox have yet to indicate when he will be back in Boston, but one would assume it will be some time after next week's All-Star break.

Editor's Note: In Some Depth will return Monday, July 22nd following the All-Star break.